1、Designation: D3880/D3880M 90 (Reapproved 2017)Standard Test Method forAsbestos Strength Units1This standard is issued under the fixed designation D3880/D3880M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method gives a procedure for the evaluation ofthe strength-giving properties of asbestos fibers used to rein-force asbe
3、stos-cement products.1.2 The purpose of this test method is to determine thenumber of strength units that may be assigned to the sampletested.1.3 Asbestos fiber possesses the ability to impart strength toan asbestos-cement product. Every fiber grade may be regardedas possessing a certain quantity of
4、 strength-giving units. Thequantity of fiber required in an asbestos-cement compositionvaries inversely with the number of strength units it possesses.For example, if an amount, designated by X, of a fiberpossessing 100 strength units produces a product of a givenstrength, 2X would be required to pr
5、oduce a product ofequivalent strength from fiber possessing only 50 strengthunits.1.4 The following definition is the basis for the strength unittest: An asbestos fiber that gives the standard strength at thestandard density when used as 10 % of the furnish is defined ashaving 100 strength units. Th
6、erefore, by knowing the percentfiber required in the mix to give standard strength at thestandard density, it is possible to calculate the strength units ofa sample of asbestos.1.5 This procedure is intended primarily for chrysotileasbestos; it has not been verified whether or not it is applicableto
7、 other types.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-con
8、formancewith the standard.1.7 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and for those with whom they come into contact.In addition to other precautions, when working with asbestos-cement products, minimize the dust that r
9、esults. For informa-tion on the safe use of chrysoltile asbestos, refer to “Safe Useof Chrysotile Asbestos: A Manual on Preventive and ControlMeasures.”21.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
10、is standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements see 6.7.2, 7.5, 9.2.2, and 1.7.1.9 This international standard was developed in accor-dance with internationally recognized
11、principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3C150 Specification for Port
12、land CementC184 Test Method for Fineness of Hydraulic Cement by the150-m (No. 100) and 75-m (No. 200) Sieves (With-drawn 2002)4C204 Test Methods for Fineness of Hydraulic Cement byAir-Permeability ApparatusC430 Test Method for Fineness of Hydraulic Cement by the45-m (No. 325) SieveC1120 Test Method
13、for Wash Test of AsbestosC1121 Test Method for Turner and Newall (T and N)Wet-Length Classification of AsbestosC1162 Test Method for Loose Density of AsbestosD1193 Specification for Reagent WaterD1655 Specification for Aviation Turbine FuelsD2590 Test Method for Sampling Chrysotile Asbestos1This tes
14、t method is under the jurisdiction of ASTM Committee C17 onFiber-Reinforced Cement Products and is the direct responsibility of C17.03 onAsbestos - Cement Sheet Products and Accessories.Current edition approved June 1, 2017. Published July 2017. Originally approvedin 1980. Last previous edition appr
15、oved in 2009 as D3880/D3880M 90(2009)1.DOI: 10.1520/D3880_D3880M-90R17.2Available from The Asbestos Institute, http:/ referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the
16、 standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accord
17、ance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1D2946 Terminology for Asbestos an
18、d AsbestosCementProductsD2589 Test Method for McNett Wet Classification of DualAsbestos FiberD3639 Test Method for Classification of Asbestos by Que-bec Standard TestD3752 Test Method for Strength Imparted by Asbestos to aCementitious MatrixE11 Specification for Woven Wire Test Sieve Cloth and TestS
19、ieves2.2 Other Standards:Quebec Asbestos Mining Association (QAMA) Standard,Designation for Chrysotile Asbestos Grades53. Terminology3.1 Definitions:3.1.1 point value, nin asbestos, an index of commercialvalue of asbestos fiber used in asbestos-cement products. Pointvalue = (SU-10)1.39 where SU stan
20、ds for strength units.3.1.2 strength unit, nin asbestos, unit of reinforcing po-tential of asbestos fiber in asbestos-cement products. Anasbestos fiber that yields a flexural modulus of rupture of 27MPa at a product density of 1.6 g/cm3when used as 10 % ofthe furnish (dry ingredients) is defined as
21、having 100 strengthunits. Therefore, the number of strength units of a givenasbestos is equal to 1000/(% fiber required in the dry mix toyield 27 MPa at 1.6 g/cm3).3.1.3 Refer to Terminology D2946 for other terms relatingto asbestos.4. Summary of Test Method4.1 This test method covers the fabricatio
22、n and flexuraltesting of asbestos-cement test specimens that contain asbestosfiber from the sample being evaluated. The calculation ofstrength units of the asbestos, based upon the flexural strength,density and composition of the test specimens, is also de-scribed.4.2 The specimen fabrication proces
23、s includes the followingsteps:4.2.1 Asbestos fiber preparation, including ball milling,fiberizing, and blending.4.2.2 Compounding, including dry mixing, the preparationof saturated water, and wet mixing.4.2.3 Test specimen formation, including the pressing ofasbestos-cement cakes in a semi-automatic
24、 press.4.2.4 Specimen curing, including a stage in a humiditycabinet, autoclaving, air cooling, and saturating in a water bath.4.3 Specimen testing, including the determination of im-mersed mass, saturated mass, flexural strength, specimenthickness and width, and dry mass.4.4 Calculations, involving
25、 the determination of specimenvolume, modulus of rupture, density, modulus of ruptureadjusted for density, asbestos fiber content required to attainstandard strength, fiber ratio required, point value, and strengthunits.5. Significance and Use5.1 This test method facilitates the comparison of differ
26、enttypes and grades of chrysotile asbestos by the property mostpertinent to its use in asbestos-cement, namely, the strength orreinforcing value it imparts to the product.5.2 While similar comparative results could be obtained onany given production equipment, this method allows the testingof small
27、samples, avoids costly interruptions in production fornumerous trial runs, and allows test values to be obtained by asingle standard method so that results can be compared amongdifferent locations.5.3 Strength Unit (SU) value of a fiber blend used inasbestos-cement products may be estimated by takin
28、g theproportionate SU value of each component of the fiber blend.5.4 If the fiber blend is formulated with the aim to optimizeanother fiber property such as filterability, the SU calculationwill assure that the blend will not fall below an acceptablestrength level.5.5 This test method is restricted
29、to grades of asbestos usedin asbestos-cement products. Very long (Group 3) fibers aredifficult to evaluate by this method because the test specimensproduced may not be sufficiently homogeneous. Similarly, veryshort (Group 7) grades may not be retained satisfactorily in themold during the pressing of
30、 test specimens or may not providesufficient strength to meet the test requirements.NOTE 1The term Group 3 or 7 refers to the standard designation forchrysotile asbestos grades established by the Quebec Asbestos MiningAssociation, See 2.2.5.6 Because of certain differences between this method andthe
31、 many variations in plant production procedure commonlyused in asbestos-cement manufacture, it is emphasized that thestrength values obtained by this standardized procedure willnot necessarily give exactly the same strength values asobtained at any one specific manufacturing plant.6. Apparatus6.1 Ba
32、ll Milling:6.1.1 Porcelain Ball Mill Jars,6meeting the followingspecifications:Capacity 11 000 cm3671 in.3External diameter 280 mm 11.02 in.Internal diameter 230 mm 9.06 in.Internal height 210 mm 8.27 in.5Available from Asbestos Institute, 1130 Sherbrooke St. West, Montreal, Q.C.,H3A2 M8.6The sole s
33、ource of supply of the apparatus (Type KU5a ball mill jars, andmachine-made balls, manufactured by Staatliche Porzellan Manufaktur, Berlin WerkSeld, Selb/afr. Hartmannstrasse 13, German Federal Republic (West Germany)known to the committee at this time is Fish-Schurman, 70 Portman Road, NewRochelle,
34、 NY. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.D3880/D3880M 90 (2017)26.1.2 Porcelain Balls,7machine made, meet
35、ing the follow-ing specifications:Diameter 40 mm 1.575 in.Mass (each) 74 to 75 g 0.163 to 0.165 lbSpecific activity 2.3 0.1 (The manufacturer specifies a nominalspecific gravity of 2.22.)Alternatively, handmade balls approaching these specifica-tions may be used.6.1.2.1 Discard balls when their diam
36、eter is 35 mm 1.38in. or less.6.1.3 Roll Table, to rotate the ball mill jars at 6.81 6 0.21rad/s 65 6 2 r/min. See Note 2.6.2 Fiberizing:6.2.1 Disintegrator,8B.O.P. (Ball, Opener, Penmen) TypeO, driven at 565 6 21 rad/s 5400 6 200 r/min by asquirrel-cage induction motor rated at no less than 1.492 k
37、W 2hp.6.2.2 Perforated Steel Discharge Plates, for the fiberizer.One each of the following opening diameters: 3, 5, 7 and 10mm, 6 3 %. Holes must be on an equilateral triangular pitchwith wire edges pointing outward.6.2.3 Cardboard Drum, approximately 410 mm 16 in. indiameter by 400 mm 15 in. in hei
38、ght with removable ringclamp on top, and canvas dust cover (transition piece) to serveas a receiver for the fiberizer discharge. Other arrangements forreceiving the fiberizer discharge that are satisfactory withrespect to relief of static pressure generated by the fiberizerrotor and with respect to
39、the prevention of sample losses andcontamination are acceptable. The free area of cloth while inoperating position must be within the limits from 1300 to 4500cm2, and the cloth must be square weave, unbleached cottonduck weighing 0.41 6 0.02 kg/m212 oz/yd2, or a cloth ofequivalent permeability.6.3 B
40、lending:6.3.1 Polyethylene Jar with Cover,9meeting the followingspecifications:Inside diameter 311 mm 12.25 in.Outside diameter 327 mm 12.875 in. (wall thickness 8 mm 0.3 in.)Inside height 311 mm 12.25 in.Other containers, such as stainless steel blenders, withsimilar internal dimensions may be used
41、.6.3.1.1 The jar may be fitted with a circumferential rubbertension band 100 mm 3.94 in. wide by 3 mm 0.125 in. thickto retain the cover. This band may be rolled down, turtleneckfashion, when the cover must be opened. Alternatively, thecover may be retained by mechanical clamps. In that case, theuse
42、 of a gasket to seal the cover may be necessary.6.3.1.2 The jar must be fitted with tires around the outerdiameter to allow it to roll on a roll table in a horizontal attitudeand to allow any clamps or projections to clear the rolls.6.3.2 Roll-Table, to rotate the blending jar at a speed of 5.876 0.
43、21 rad/s 56 6 2 r/min. See Note 2.6.3.3 Rolling Sheet, 1m21 yd2 or larger, made of rubber,plastic, or some other flexible elastomer.6.4 Dry Mixing:7The sole source of supply of the apparatus known to the committee at this timeis Ateliers de Lessines S.A., Division BOP, 55 rue de Wauthier 1020, Bruxe
44、lles,Belgium. If you are aware of alternative suppliers, please provide this informationto ASTM International Headquarters. Your comments will receive careful consid-eration at a meeting of the responsible technical committee,1which you may attend.8The sole source of supply of the apparatus known to
45、 the committee at this timeis Canadian Laboratory Supplied Limited, Box 2090 Stn. St. Laurent, Montreal 307,P. Q., Canada. Specify dimensions required, request a design similar to Catalog No.J3028, and refer to Canlab Quotation No. 2713 (1969). If you are aware ofalternative suppliers, please provid
46、e this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.9The sole source of supply of the apparatus known to the committee at this timeis Canadian Laboratory Supplies Limited, Box
47、2090, Stn. St. Laurent, Montreal 307,P. Q., Canada, (Catalog No. J3028-14). These must be fitted with suitable vanes. Ifyou are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the respo
48、nsible technical committee,1which you may attend.FIG. 1 Wet-Mixer AssemblyD3880/D3880M 90 (2017)36.4.1 Polyethylene Jar with Cover,9meeting the followingspecifications:Inside diameter 248 mm 9.75 in.Outside diameter 257 mm 10.125 in.Inside height 273 mm 10.75 in.Capacity 13 200 cm3Other containers,
49、such as stainless steel mixers, with similarinternal dimensions may be used.6.4.1.1 The jar must be fitted with a rubber band asdescribed in 6.3.1.1.6.4.1.2 The exterior of the jar must be fitted with tires asdescribed in 6.3.1.2.6.4.1.3 The interior of the jar must be fitted with threemixing vanes located 2.09 rad 120 apart, along the fulllength of the jar and projecting 38.1 mm 1.5 in. from theinside wall. The vanes may be fastened to the wall by smoothhead rivets or a
